Squirrel-cage rotor.



F. W. STEPATBR.

SQUIR-REL GAGB'ROTOR.

APPLICATION FILED APR.14. 1913,

Unrrnn sTATEsigr-ENT OFFICE.

.FRANK W. STEFATEB, F LQJSVILLE, KENTUCKY, ASSIGNOR T0 JAS. CLARK, JR.,

ELEGTRI SG., OF LOUISVILLE, KENTUCKY, A CORPORATION 0F KENTUCKY.

SQUIRREiL-GAGE KOTOR.

To oZZ whom t may conce/m:

Be it known that I, Fawn. VJ. Seemann, a citizen of the United States,` residing at Louisville, in the county of Jefferson and State of Kentucky, have invented certain new' and usefni improvements in Squirrel- Cage Rotors, ci. which the foliovving is a specification'. .i

The principal object of my invention. is to provide a new and improved construction of squirrel cage rotors for alternating cnrrent induction motors.

Another object of my invention 'is to provide means 'for locking the bars-and end rings of a squirrel cage rotor securely to gether. I

These and other objects of my invention will be made apparent in the 'following specification and claims taken in connection with the accompanying drawings, in which I have illustrated one specific embodiment of my invention. It Will be understood that vthe invention is defined in the appended claims.

Referring to the drawings--Figure l is an axial section of a squirrel cage rotor ein bodying my invention. Fig. 2 is an end elevation of the same; and Figs. 3 and d are fragmentary end elevations showing the device at intermediate stages in its 'manufacture'.

The rotor spider 6 is adapted to ce mountved on a shaft and secured by a'key in the key-slot 7. Adjacent to the spider are the two clamping rings '8, adapted to be held in place by the bolts 9 and nuts 10 Between the clamping rings are the aminae 11 secured in alinement by the key 1Q. The laminae are slotted and each slot contains a respective bar 13 Wrapped with fiber 147 or other suitable insulating material. The end "rings 15 have radial notches 16 cut therein to receive the ends of the bars 13. The dimensions/of the bars 13 and notches 16 are such that the bars make a driving iit in the notches. The ends of the bars 13 are driven into the notches 16 in an inward radial directicn, and the driving it insures goed electrical contact. After the bars have all been 'dr"'.venl in place in the notches the rotor is pnt in a lathe and a groove or channel 18 is turned in the outer tace ot each ring, cut- Specicationet Tictterslatent.

Applicaton filed April TA, W13.

Patented Mar. 10, 1914,.

Serial ne. 761,037.

ting alternately through the ends of the bars 13 and the projecting teeth 17 of the ring i5. After this channel is cut a ring 19 is fitted tightly into it and secured by peening the edges of the channel over upon the ring. The meeting ends of the ring 19 are designated 20 in Fig. 2.

It will be seen that the end rings and the bars of the squirrel cage can be given a plain, simple form prior to assembling, such as Willi be very inexpensive in manufacture. The parts can be quickly assembled in the manner described and locked together as a" Wnoies no detail work on each joint being rerpiired.- The ioclring ring 19,- engaging the ends of the bars and the teethialterna'tely, securely locks the bars aga-inst centriinga force.

claim:- i.. A, squirrel cage rotor comprising end rings with radial notches therein and with radial teeth between the notches, bars fitting tightly in said notches, each said end ring having an annular groove turned in its face cutting alternately through the said teeth and the ends of the said bars, and a locking ring in said groove.

2. A squirrel cage rotor comprising end rings and bars engaging the same, each said end ring and said bars having an annuiar groene turned in the face of the ring cutting alternately through portions of the ring and the bars, and a locking ring in said groove.

3. A squirrel cage rotor comprising end rings and hars engaging the same, and a single iocking ring engaging' the ends of the bars andthe intermediate portions of the ring alternately and-thereby securing the ends of the bars to the rings.

4. A squirrel cage rotor comprising end rings and bars in combination. said rotor having a groove at each end cutting through the ends of the bars and the intermediate portions of the respective end ring in alternation, and a locking ring in said groove securing the parts together.

5. A squirrel cage rotor comprising` end rings and bars in combination, said rotor lhaving a groove at one end ther-eo?L cutting across the-bars and across the intermediate portions of the respective end ring, awall 

